ASCII

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ASCII (an acronym for American Standard Code for Information Interchange) is an encoding for various glyphs (written forms such as letters, numbers, etc) into 7-bit numeric form.

Originally based on the English alphabet, the supported set for ASCII includes not only numbers, letters (upper- and lower-case) but also punctuation, and other special-purpose characters (from then-common ones like '@', '#', etc, to others that ASCII has made popular - '^', '|', etc). It also includes non-printing characters used for control of printing terminals - tab, line feed, carriage return, etc.

ASCII was developed in the early 1960s from telegraph code. Its first commercial use, in 1963, was as a teleprinter code promoted by Bell data services for the TWX network. Later, it was adopted for use by terminals, line-printers, etc, as well as by secondary storage and files.

ASCII soon superseded an earlier wide-spread encoding, SIXBIT, which allowed 6 characters to be carried in the then-common 36-bit words common on many computers (but only supported upper-case characters). IBM had its own competing encoding standard at the time, EBCDIC, which ASCII has also gradually superseded.

ASCII was eventually used by personal computers such as the Apple II, and the IBM PC. IBM extended the character set with a separate set of glyphs used for line drawing; the first of many often-incompatible extensions to ASCII for various national, etc, usages. It has now been superseded for the WWW by UTF-8, which is however backwards compatible with ASCII.

ASCII table

Here is a table of the ASCII characters. The 'Character' column gives either i) the character itself (if only a single character is there), or ii) its name (if two or more characters are shown). The 'Input' column shows what to type on most keyboards to generate that character.

Decimal Octal Hex Character Input Description
000 000 00 NUL ^@ Null character
001 001 01 SOH ^A Start of Heading
002 002 02 STX ^B Start of Text
003 003 03 ETX ^C End of Text
004 004 04 EOT ^D End of Transmission
005 005 05 ENQ ^E Enquiry
006 006 06 ACK ^F Acknowledge
007 007 07 BEL ^G Bell
008 010 08 BS ^H Backspace
009 011 09 HT ^I Horizontal Tab
010 012 0A LF ^J Line Feed
011 013 0B VT ^K Vertical Tab
012 014 0C FF ^L Form Feed
013 015 0D CR ^M Carriage Return
014 016 0E SO ^N Shift Out
015 017 0F SI ^O Shift In
016 020 10 DLE ^P Data Link Escape
017 021 11 DC1 ^Q Device Control One
018 022 12 DC2 ^R Device Control Two
019 023 13 DC3 ^S Device Control Three
020 024 14 DC4 ^T Device Control Four
021 025 15 NAK ^U Negative Acknowledge
022 026 16 SYN ^V Synchronous Idle
023 027 17 ETB ^W End of Transmission Block
024 030 18 CAN ^X Cancel
025 031 19 EM ^Y End of medium
026 032 1A SUB ^Z Substitute
027 033 1B ESC ^[ Escape
028 034 1C FS ^\ File Separator
029 035 1D GS ^] Group Separator
030 036 1E RS ^^ Record Separator
031 037 1F US ^_ Unit Separator
032 040 20 SP   Space
033 041 21  !
034 042 22 "
035 043 23 #
036 044 24 $
037 045 25  %
038 046 26 &
039 047 27 '
040 050 28 (
041 051 29 )
042 052 2A *
043 053 2B +
044 054 2C ,
045 055 2D -
046 056 2E .
047 057 2F /
048 060 30 0
049 061 31 1
050 062 32 2
051 063 33 3
052 064 34 4
053 065 35 5
054 066 36 6
055 067 37 7
056 070 38 8
057 071 39 9
058 072 3A  :
059 073 3B  ;
060 074 3C <
061 075 3D =
062 076 3E >
063 077 3F  ?
064 100 40 @
065 101 41 A
066 102 42 B
067 103 43 C
068 104 44 D
069 105 45 E
070 106 46 F
071 107 47 G
072 110 48 H
073 111 49 I
074 112 4A J
075 113 4B K
076 114 4C L
077 115 4D M
078 116 4E N
079 117 4F O
080 120 50 P
081 121 51 Q
082 122 52 R
083 123 53 S
084 124 54 T
085 125 55 U
086 126 56 V
087 127 57 W
088 130 58 X
089 131 59 Y
090 132 5A Z
091 133 5B [
092 134 5C \
093 135 5D ]
094 136 5E ^
095 137 5F _
096 140 60 `
097 141 61 a
098 142 62 b
099 143 63 c
100 144 64 d
101 145 65 e
102 146 66 f
103 147 67 g
104 150 68 h
105 151 69 i
106 152 6A j
107 153 6B k
108 154 6C l
109 155 6D m
110 156 6E n
111 157 6F o
112 160 70 p
113 161 71 q
114 162 72 r
115 163 73 s
116 164 74 t
117 165 75 u
118 166 76 v
119 167 77 w
120 170 78 x
121 171 79 y
122 172 7A z
123 173 7B {
124 174 7C |
125 175 7D }
126 176 7E ~
127 177 7F DEL   Delete

See also